20 H. B. FANTHAM. 
Spirochetes may at times be seen vibrating in two halves 
about their central points as nodes; they then bear a general 
resemblance to two tuning-forks joined by their single ends 
and in vibration. 
Slowly moving specimens of 8. anodonte may curl up 
one end (PI. 3, fig. 35; also PI. 2, fig. 33, and text-fig. 2), 
usually the hinder one, judging by the direction of motion. 
This may be carried still further in the case of very slowly 
moving specimens where each end of the organism coils up, 
and one gets figures like that shown in text-fig. 3, where two 
loosely coiled watchspring-like curves face each other, and 
are conjoined in the middle (cf. also Pl. 3, fig. 36). 
These Spirochetes seem to move more quickly than Try- 
Text-Fig, 3.—Outline of very slowly moving specimens of 
S. anodonte, with each end coiled. 
panosomes, and with an added corkscrew motion. I am 
aware that Trypanosomes sometimes turn over during move- 
ment, but the membrane in the case of these undoubted 
Flagellates is a strict lateral outgrowth of the body, and not 
spirally wound, while there is a long, free flagellum. The 
membrane also vibrates in the case of Trypanosomes, while 
there is little of this vibratory movement connected with the 
membrane of Spirochetes. I consider that the membrane of 
Spirochetes is attached to the body in the form of a spiral, 
or, more precisely, that it is a spirally arranged lateral 
extension of the periplast, and that its spiral winding is not 
merely due to a torsion of the free part of a lateral membrane, 
which may untwist (as Woodcock seems to suggest [24, p. 
221]). The constant spiral movement: of Spirochetes, I 
think, bears out the correctness of the view herein set forth, 
